It has been found highly advantageous, where possible, to form valve bodies and other pressure vessels from rolled steel shapes, wherein the material is generally denser and of greater uniformity than can usually be achieved with metal castings. For example, ball valves, check valves and the like are commonly formed with a main body band of cylindrical or spherical configuration, with at least one full size end opening through which a ball, clapper, plug or other closure member can be inserted. In completing fabrication, this opening is covered with an end closure carrying a hub for attaching the valve member into a pipeline. When forming the end closure of steel plates, it is conventional practice to form it in at least two pieces, one a flat plate with a large central opening which is bolted or otherwise secured to a main body member, and the other a cylindrical pipe which is welded into the opening for installation in a pipeline. Often, recesses are cut into the flat plate to accomodate sealing rings which engage against the valve member to effect a seal. The main body member, then, must be wide enough to cover the valve member and span the space between the two flat inner surfaces of the opposing end closures.